-CLINICAL RESULTS AND PATIENTS' REACTIONS"
Andrzej Czyzewski & Bozena Kostek Technical University of Gdansk Sound Engineering Department ul.Narutowicza 11/12,80-952 Gdansk,Poland Marek Roland - Mieszkowski Digital Recordings - Advanced R & D 5959 Spring Garden Rd., Suite 1103 Halifax, Nova Scotia B3H-1Y5,Canada Copyright 1990-1994, Digital Recordings Halifax, Nova Scotia, Canada Introduction ************ New electronic aid / training device to reduce stuttering was developed. Clinical tests on about 60 patients showed, that the DSA (Digital Speech Aid) is effective in helping to combat stuttering by itself or in combination with other standard and non-standard methods . The majority of "Classical Stutterers" become more fluent when using this device. Device is relaxing and non-disturbing. With DSA a person can speak in any fashion and at any rate. DSA is based on advanced DSdP (Digital Sound Processing) technology using the latest electronic DSP technology. The software developed for the device exploits new approach to stuttering disorder. With DSA many stuttering people can speak fluently (or more fluently) in any fashion and at any rate. Results of the DSA testing supports authors' theory, that stuttering is a physiological disorder, in most cases of a neurological basis. Stutterers become nervous because they stutter (not as believed by some, that they stutter since they are nervous). Clinical testing of Digital Speech Aid (DSA) ******************************************** Authors decided to test DSA in real life situations, rather than in artificial, laboratory-based. There are two major reasons for this : * Very often results in the laboratory introduce unrealistic environment, which does not predict at all if the device or technique will be effective in other situations, where other conditions such as : stress, multitasking, different auditory conditions etc may play important role. * Effects of DSA are sometimes not noticable or significant at the first trials. Our experiments indicate, that 4 to 6 weeks are required to obtain full benefit of given type of DSdP processing.In all clinical cases improvement was observed with similar time scale. No decrease of effectiveness was observed as predicted by some people familiar with our early research. Above mentioned reasons require portable device to perform experiments. This was the reason that DSA was reduced, despite its' complexity to very small size. This allowed authors to perform experiments investigating long-term effects. Also DSA was designed with very powerful hardware, capable to implement all existing algorithms and many new ones, which are currently under investigation . Currently, DSA is most effective in the case of "Classical Stutterers" who consist about 80% -> 90% of the stuttering population. Significant improvement or total fluency is observed in about 40% -> 60% of "Classical Stutterers" during the text reading. Rest of them also improve to various degrees. Improvements were also observed in all situations : in the office, at home, on the telephone, during public meetings, presentations, good and bad days, etc. Improvement is instant, however, we observe increase in effectiveness during the first 2 -> 6 weeks (this is consistent with other similar observations and could be explained in author's opinion on the bases of neural networks, which could be used as the model of inner-working of the auditory system). After that it seems to remain the same. In majority of cases there is a carryover effect - person remains more fluent for 2 hours -> 2 weeks after using DSA. Significant improvement in self-esteem and self-confidence are observed. People like to use DSA and say that it is relaxing. Many people also indicate, that they feel, that they cannot stutter. Long term effects seem to support authors' theory and expectations - DSA is still effective (same level) after being used for 10 months. First clinical trials - June 1992 ********************************* First prototypes of DSA (II generation) were finished in May 1992. Some of the first clinical trials were very exciting and the device met with good approval from the stuttering people. Here are some of the remarks from this early study in Poland : * Testimony from speech pathologist : " ...I think that Digital Speech Aid (DSA)is extremely effective in the elimination of stuttering, even in cases of very severe stuttering. ....During my 30-years long practice as a speech pathologist, no technique was as successful. I believe that we finally have the green light for people who have till now problems with elimination of stuttering ...We are waiting very anxiously for DSA to appear on the market and become available for all stuttering people......" Halina Stawikowska, Speech Pathologist, June 04, 1992. * "....Speaking with DSA brought me big relief. I realized, that I can also speak like normal person, at relatively fast rate.All the sudden I got new surge of power.....This device helped me also in the inter-personal contacts. I am not afraid anymore !..It is fantastic to realize, that spoken word does not have to be "bumpy". Thank you , thank you, thank you !!!....", Anna Grudzien, 21 years old, June 05, 1992. * ".... Speaking with DSA eliminates prolongation of vowels, speech becomes more fluent...Improvement is very good, much better then with the DAF (Delayed Auditory Feedback). In my case it was particularly noticeable in the German language, which I am studying and in which I stutter much more often then in the Polish language. While reading in German, with DSA I did not stutter at all....", Jacek Szot, 24 years old, June 03, 1992. * "... I think, that use of DSA is relaxing.It is difficult to stutter. I could speak fast without stuttering. Normally I speak slow......", Prof. Antoni Stawikowski, Astrophysics, May 31, 1992. * ".... With DSA one can speak fast ,with any chosen speed. I went with this device to do shopping and I could speak very well.I am sure,that if I would have this device my speech will improve...", Lukasz Jaskolka, 15 years old, June 04, 1992. * "..... using DSA I feel, that I cannot stutter and I am not nervous. On the beginning, I did not believe that I can stop to stutter. After use of this device I got back my confidence... Stuttering people must always speak slow, however I am not used to do that. Using this device I can speak very fast.....", Emila Davidek, 13 years old, June 04, 1992. * ".... when I tried this invention I started to feel unconstrained, free, I am not stressed and I do not stutter.This device is very good..", Marek Struk, 9 years old, June 04, 1992. Long term effects - DSA (III-d generation model) ************************************************ Long-term effects were and are tested right now. The initial results are very encouraging. It is expected that due to the relaxing and reassuring effect of DSA, the base-line stuttering level will decline (we observed this already in some cases). The effectiveness of the device is expected to remain the same for removal of the "natural level" of stuttering. In a sense DSA is expected to work as a prosthetic device, similar to hearing aid. It does not mean however, that it has to be worn all the time. It can be only used several hours per day, in the most difficult situations and as a backup (many of our subjects are using it in this mode). Below are some remarks from some patients who did use DSA for over period of 3 to 10 months : * "....I am very happy with DSA. Used it day to day and my speech has improved 80 %. I have used DSA to speak at approx. twenty (20) meetings as I am president of a Legion in Dartmouth, N.S......I recommend DSA 100%....." John Dunphy, Dartmouth, Nova Scotia, Canada, November 18, 1993. * "...my experience with DSA for past 7 months has been good....In past years talking on the phone was my reason to be nervous to speak to people. With DSA I now find it to be no problem to answer a phone and have a normal conversation. I recommend DSA for anyone with a speech stoppage and stuttering." John Dunphy, Dartmouth, Nova Scotia, Canada, March 25, 1994. * "Overall the device has been very helpful...I have improved the most on the telephone; I would often avoid words, but with the device I hardly stutter... I am not as apprehensive about my stuttering as before and my speech has improved a great deal. I have also noticed an increase in my self-esteem since wearing the device...I feel more confident in speaking situations and do not avoid words.... For the first few weeks (3-4), my speech was improving at a steady rate. At about one month, my level of fluency seemed to level off and I have maintained the same level of fluency since that time...." 25 years old female stutterer, Halifax, Nova Scotia, Canada November 18, 1993. * "..Over the course of a few months, I became very comfortable with the speech device (DSA). ...I have less apprehension with "feared words" and stutter quite a bit less than before using the device. My confidence in speaking has improved over the time I used the device and the "carry-over" time has also increased. My fluent speech will last sometimes half a day without the device." 25 years old female stutterer, Halifax, Nova Scotia, Canada, December 19, 1993. * "The DSA machine has really opened up a new world for me. It has provided me with a new sense of freedom now, by allowing me to speak without fear, of so many things. The most significant revelation is being able to use the telephone and call people and places I haven't been able to.... The DSA has given me so much comfort in my speech and day to day life by gently allowing me to speak and say words that I have avoided for many, many years. It is truly a great invention and a miracle for someone like myself who felt I would spent the rest of my life hiding from many situations." Lori Paruch, Halifax, Nova Scotia, Canada, January 14, 1994. * "When I first began to use the DSA I noticed a dramatic increase in my fluency when speaking especially on the phone.....It has been so wonderful to have the freedom of not being afraid to use the phone, to call to make appointments etc.....My life has changed now since I have used DSA.....it is a wonderful machine to use." Lori Paruch, Halifax, Nova Scotia, Canada, April 04, 1994. Comparative study of various methods for the ******************************************** modification of the auditory feedback loop ****************************************** As the elaborated prototypes of the DSA are implementing various algorithms for the modification of the auditory feedback loop,thus some studies were carried out to enable the comparison of the effectiveness of individual methods. The DSA prototypes were implementing masking noise (MAF), delayed auditory feedback (DAF), frequency altered feedback (FAF) [4,5] and digital discorrelation filtering - the algorithm elaborated by the authors  and various combinations of the above algorithms. Results of an exemplary testing session are presented in the Tab. 1 and in Fig. 1,2,3. Tab.1 Number of errors occured during the testing session Patient Direct MAF discorrel. discorrel. FAF FAF+DAF speech filtering 1 filtering 2 Filip 23 9 9 12 5 2 Jacek 24 10 22 29 10 2 ukasz 8 2 2 4 1 0 Krzysztof 10 3 9 13 7F 0 *** Fig. 1 *** Fig. 1 Number of errors for individual patients according to Tab.I. *** Fig. 2 *** Fig. 2 Relative number of errors expressed in [%]. *** Fig. 3 *** Fig. 3 Comparison of results obtained with all methods. Conclusions *********** DSA was designed with very powerful hardware, capable to implement all existing algorithms and many new ones, which are currently under investigation The elaborated prototypes of the DSA are provided with 256 settings to be selected by the operator or by the user. Currently, DSA is most effective in the case of "Classical Stutterers" who consist about 80% -> 90% of the stuttering population. Significant improvement or total fluency is observed in about 40% -> 60% of "Classical Stutterers" particularly during the text reading. Rest of them also improve to various degrees. Long term effects seem to support authors' theory and expectations - DSA is still effective (same level) after being used for 10 months. Consequently, the authors are of the opinion that the progress in modern digital signal processing technology may cause considerable impact to the reduction of stuttering. References **********  Hermes Electronics, internal report "The Digital Speech Aid", Halifax, Nova Scotia, Canada, December 1993.  Howell P., Nirit El-Yaniv, Powell D. J.: "Factors Affecting Fluency in Stutterers when Speaking under Altered Auditory Feedback", Speech Motor Control and Stuttering. Excerpta Medica Nr 9 1991, chapter 28.  M. Roland-Mieszkowski et al.: DSA (Digital SpeechAid) - A New Device to Decrease or Eliminate Stuttering.Paper presented at 1st World Congress on Fluency Disorders, Munich, Germany, 1994.  Howell P.: "Changes in voice level caused by several forms of altered feedback in fluent speakers and stutterers," Language and Speech, 1990, 33(4), pp.5-338.  Webster R. L.: "Manipulation of vocal tone: implications for stuttering", Speech Motor Control and Stuttering. Excerpta Medica No., 1991.